Search

The natural hydraulic connections between cascade hydropower may make hydraulic and electric connections mismatch after the market clears. Aiming at relieving the contradiction between water surplus and water shortage after market clearing, this paper proposes a new market clearing method considering the coupling relationship between water and electricity. And the method is verified by the simulation of a virtual spot market consisting of eight stations in Sichuan Province, China. The main contributions of this paper lay on three aspects: firstly, a new index called water-electricity coupling degree (WCD) and its calculation method are proposed to measure the overall situation of water shortage and water abandonment in the clearing results. Secondly, a multi-objective clearing model for cascade hydropower stations is established with the goal of minimizing power purchase cost and maximizing WCD. Thirdly, a solution method combined with the characteristics of the clearing model is developed. The case results demonstrate that the built model increases the WCD value by 1.57 % and reduces the insufficient output and surplus water by 45.18 % without increasing the power purchase cost of the power grid; The proposed solution strategy lowers the complexity of the model and improves the solution efficiency, where the search space reduction and time period merging strategies can reduce the calculation time by about 3 % and 8 % respectively. The new clearing method provides a new idea for solving the uncoupling problem of water-electricity-price in the cascade hydropower spot market. • Propose a new index called water-electricity coupling degree (WCD). • Establish a multi-objective clearing model for cascade hydropower market. • Develop a model dimensionality reduction strategy for model solution. [ABSTRACT FROM AUTHOR]

The existing research on the multiple fluid control valves to control the balanced exploitation of natural gas in horizontal wells lacks theoretical model support. On this basis, this paper established a flow rate and pressure model of the segmented horizontal well based on the fluid control valve. The model considers the throttling performance, installation position and opening adjustment step size of the fluid control valve for the first time. Next, systematically analyzed the mechanism of mutual influence of the opening and the position on the flow rate and pressure based on multiple fluid control valves. In addition, a novel method of using the dichotomy model to adjust the production of different production segments was proposed to analyze the horizontal wells of 15 production segments in Sichuan. It was found that when the opening adjustment step size is less than 5%, the natural gas production shows irregular changes, which makes it hard to effectively control the production of each segment. When the step size is 5%, the maximum production variation is 2.7%, which will have a more significant and meaningful effect on the exploitation of natural gas. Through seven iterations, the maximum production errors of high and low production segments are 1.3 % and 1.1 % respectively, both less than 2.7%. The research results verified the correctness of the theoretical model of segmented horizontal wells based on multiple fluid control valves. This research provided a theoretical basis for the opening control of multiple fluid control valves based on different production segments of horizontal wells. • Established a flow rate and pressure model of segmented horizontal wells based on the fluid control valve. • Found the minimum adjustment opening for the numerical simulation of the balanced exploitation in horizontal wells. • Proposed a novel dichotomous method to adjust the production of different segments in the horizontal well. [ABSTRACT FROM AUTHOR]

With the completion of the poverty alleviation task in China, the Chinese economy has made great breakthroughs. Meanwhile, the implementation of Chinese "dual carbon" goal has entered an important window period of both strategic opportunities and difficulties. The emission of carbon dioxide (CO2) leads to the greenhouse effect, which affects the sustainable development of society. Therefore, this paper proposes an improved analytic hierarchy process (AHP) with Slacks-based measure integrating data envelopment analysis (SBMDEA) (AHP-SBMDEA) based efficiency evaluation model for different provincial-level administrative regions in China, which is used to analyze and optimize the Chinese energy structure of different provincial-level administrative regions. With coal, gasoline, petroleum, fuel oil, diesel, crude oil and natural gas as inputs, the per capita Gross Domestic Product (GDP) as the desired output and the CO2 as the undesired output, after linear weighted calculation of the results of the AHP-SP model and the SBMDEA model, the energy efficiency evaluation model of different provincial administrative regions in China is established. The results show that there is a large difference in efficiency between Chinese northern and southern regions, and the overall efficiency of southern regions is higher than that of northern regions. In addition, it is easier to find out the optimal energy efficiency benchmark, which can provide suggestions and help to guide the energy consumption input structure improvement of other inefficient provincial-level administrative regions. Furthermore, the energy structure can also be adjusted through the redundant variable calculated by the SBMDEA model. For example, Sichuan Province can reduce the consumption of the coal, the gasoline, the diesel, the fuel oil, the crude oil and the natural gas by 5269.95 × 10000 tons (WT), 513.01 WT, 59.05 WT, 34.37 WT, 4,73.33 WT and 130.37 billion cubic meters (BCM), respectively. Its CO2 emissions can be reduced by 1925.4 WT, and raise the efficiency of energy utilization in the province. [Display omitted] • Novel economy and CO 2 emissions evolution model based on a AHP-SBMDEA is proposed. • The proposed model can identify the optimal energy efficiency benchmark. • GDP per capita can be increased and CO 2 emissions can be decreased. [ABSTRACT FROM AUTHOR]

Coordinating the relationship between the national pipeline network company and the provincial natural gas company is the most crucial contradiction in China's natural gas market reform. This paper innovatively incorporates the comprehensive evaluation method, modified spatial gravity model, and social network analysis method to investigate the regional natural gas market to solve this dilemma. The result of the case study is as follows. (1) The development of the natural gas market in China's provinces is uneven, among which resourceful provinces and eastern provinces are relatively strong. (2) The densely connected areas of the natural gas market are mainly concentrated in the Beijing-Tianjin-Hebei region, the Yangtze-River-Delta region, and the Sichuan-Chongqing region. (3) Our work can clarify the node attributes and different efficacy of provinces. The core provinces all belong to the net spillover block, and they are located at key positions and roles in the obtained spatial correlation network. (4) Market participants, commodity diversification and openness are the prominent factors influencing the proposed spatial correlation network. This paper's major achievement is the reasonable division of five regional natural gas markets. The conclusion can help policymakers clarify the overall natural gas market spatial pattern and provinces' market potential and functions. • This article analyzes the construction plan of regional natural gas market in China. • We builded a comprehensive quality evaluation system for the natural gas market. • We used the modified spatial gravity model to calculate the interprovincial natural gas spatial influence. • We used centrality and structural holes to analyse individual network attributes. • We applied edge-core structure and block model to analyse the overall network structure. [ABSTRACT FROM AUTHOR]

As an institutional innovation in the market-oriented reform of China's energy sector, the policy effect of energy consumption license transaction (ECPT) is still lack of research. The pilot provinces of energy market-oriented reform are relatively scattered. Therefore, this paper aims to evaluate the spillover effect and regional differences of ECPT, so as to make up for the lack of research on China's market-oriented energy reform. Results show that ECPT has inhibitory effects on energy consumption and energy intensity. In addition, ECPT can reduce energy consumption and energy intensity in neighboring areas. The policy effect of ECPT shows the characteristics of strengthening with the evolution of time. Foreign trade, industrial structure and technological progress are the paths for ECPT policies to promote energy transformation. The implementation effect of ECPT shows significant regional differences, which has a significant role in promoting the energy transformation of Henan and Sichuan. Therefore, the central government must ensure the continuity of energy market-oriented reforms to release long-term policy dividends. Pilot provinces should not only play the role of domestic regional energy-saving cooperation, but also strengthen foreign trade and technological innovation to promote energy transformation. • ECPT has an obvious inhibitory effect on energy consumption and energy intensity. • ECPT has the spillover effect of energy saving on neighboring provinces. • The long-term effects of ECPT are stronger than the short-term effects. • Foreign trade, industrial upgrading and technological progress are the mechanisms. • The effect of ECPT shows significant heterogeneity in different pilot provinces. [ABSTRACT FROM AUTHOR]

The energy crisis is a major challenge to sustainable development. Governments therefore constantly seek ways to improve energy conservation. In this paper, our goal was to promote energy conservation and simultaneously increase employment. First, based on China's current regional energy conservation model, social energy costs and employment factors are comprehensively considered to construct an inter-provincial cooperative energy conservation model, the minimal core method is used to construct a cooperative interprovincial benefit-distribution model. Second, representative regions of China (Beijing, Shanghai, Shanxi, and Sichuan) were selected to demonstrate the model in an empirical analysis of cooperative provincial energy conservation. It was found that the total employment in Beijing, Shanghai, Shanxi, and Sichuan can be increased by 9.84 × 106 persons, and the total social energy cost can be decreased by US$59.22 × 106. The cooperative benefit distribution model can increase the total benefit by US$65.28 × 106. Finally, to verify the robustness and feasibility of the model, the sensitivity of the model to these changes is analyzed by changing the parameter values, and it was found that the model was both robust and feasible. The research results provide a new way to improve China's current energy conservation model. • The inter-provincial cooperation model for employment and social energy costs (i.e. bi-objective model). • Constructs a social energy cost function. • Considers energy structure factors. • Uses the minimal core method for benefit distribution. [ABSTRACT FROM AUTHOR]